It is possible to prevent processing gases from being mixed when alternately supplying the processing gases while alternately switching the processing gases and to suppressed a transient phenomenon more efficiently as compared to conventional cases. A second distributed Bragg reflector includes first and second portions. The leg is articulated with at least one spring-loaded joint to simulate a real horse’s leg and train the farrier in proper shoeing techniques. The other secondary winding is connected to the first secondary winding through two diodes that are not conducting during the measurement but do conduct if the capacitor being measured has an electrical charge. The pull up tree system can support a regularly arranged artificial tree andor an inverted tree.